more air bubbles but not actually above the water

so i was just killing salmon in a river, and when i get close to the top of the water, but im not outside of the water, i start gaining my air bubbles back.

I dont think this is intentional.

I have no idea how to submit a video of it happening or else i would, but what i was doing was i killed some salmon at the bottom of the lake, then went close to the top of the surface but didnt go above it and i was gaining air bubbles back.